VFP-package {VFP}R Documentation

(V)ariance (F)unction (P)rogram

Description

The intended use of this package is to implement variance functions proposed in Sadler's VFP stand-alone software (see reference below), from which the name was borrowed as well. Main function of this package is fit.vfp for fitting non-linear variance-function models. Usually, these models are fitted to analysis-results of precision performance data e.g. frequently generated for in-vitro diagnostics (IVD). R-package VFP is designed to work best on objects of class 'VCA' as generated by R-package VCA but it is not restricted to these. There are several functions operating on S3-objects of class 'VFP', e.g. plot.VFP, print.VFP, summary.VFP, and predict.VFP. Function predictMean is of special interest when a functional relationship is used to derive limit of quantitation (LoQ) or functional sensitivity, as the concentration at which the IVD-imprecision expressed as coefficient of variation (CV) undercuts a specific threshold.

Details

Package: VFP
Type: Package
Version: 1.4.1
Date: 2022-11-08
License: GPL (>=3)
LazyLoad: yes

Author(s)

Andre Schuetzenmeister andre.schuetzenmeister@roche.com, Florian Dufey florian.dufey@roche.com, Andrea Geistanger andrea.geistanger@roche.com

References

CLSI EP05-A3: Evaluation of Precision of Quantitative Measurement Procedures; Approved Guideline - Third Edition. (2014) Sadler WA, Smith MH. Use and Abuse of Imprecision Profiles: Some Pitfalls Illustarted by Computing and Plotting Confidence Intervals. Clin Chem 1990; 36/7:1346-1350

Sadler WA, Smith MH. A reliable method of estimating the variance function in immunoassays. Comput Stat Data Anal 1986; 3:227-239

Sadler WA, Smith MH. Estimation of imprecision in immunoassays quality assessment programmes. Ann Clin Biochem 1987; 24:98-102

Sadler WA, http://www.aacb.asn.au/professionaldevelopment/useful-tools/variance-function-program-version-110. Accessed November 16, 2015


[Package VFP version 1.4.1 Index]